Evidence of (some) "asterina" / aquilonastra stars eating (some) zoanthids

[VintageReefer]

I had NO CLUE, but figured a few dozen stars would feed a shrimp…guess I was wrong..

added: that’s what I get for inadequate research before purchase

I can’t afford $20/week to feed a pair of shrimp, looks like I need to find a tide pool somewhere…
thank you

Asterina starfish farm for future harlequin shrimp and Aiptasia farm.

P1 I would like to farm Asterina starfish that my LFS gave to me (15 starfish), how could I do this? I want them to lay asterina eggs, or do they even do that? Is there a way to make them reproduce asexually or by fragging (slicing them in half) to make them grow? I have already done this with...

www.reef2reef.com

Each harlequin eats around 15 asterina per day. So a pair would eat 30 a day, around 900 asterina a month

Or, 1 chocolate chip star each per week

Now some have methods where you have several chocolate chip star, around 6-7. Remove one leg from one chocolate chip at a time and rotate which one you take from, and allow them to regrow. However I talked to my lfs, and the guys there all own harlequin in home tanks and they say they have never been successful with this strategy and it takes a long time for a leg to regrow.

Best bet - sell to a LFS for credit. Mine told me they would gladly buy him back after the tank was cleaned up

 

[Doctorgori]

Each harlequin eats around 15 asterina per day. So a pair would eat 30 a day, around 900 asterina a month

Appreciate that…
I thought you might find some humor in this then:
ebay never fails to amuse

guess I’ll have to save my allowance or cut back on my pricey single barrel bourbon habit

 

[VintageReefer]

Appreciate that…
I thought you might find some humor in this then:
ebay never fails to amuse

guess I’ll have to save my allowance or cut back on my pricey single barrel bourbon habit

20 for 80$?! Sheesh I should have bagged them and sold them lol

Etsy doesn’t fail either. Guess this guy got fed up with them and 3d printed his own removal scoop

Asterina Magnetic Scooper - Etsy

This Aquariums & Tank Decor item by Printed3dParts has 3 favorites from Etsy shoppers. Ships from Houston, TX. Listed on May 18, 2024

www.etsy.com

 

[twentyleagues]

regardless they overpopulate, then become unsightly

John Maloney of Reef Cleaners will hook you up, I got a pair ($80) arriving today as a matter of fact…timely thread

Was wondering how much food a pair of harlequins require: As above, pair arriving today, I have three tanks with these pesky stars, my thinking was house the harlequins in the sump and net off the stars from all three tanks… I am told you can collect starfish, no clue where to find them



true and anything that overpopulates will get less picky. My plan is remove em all, let the harlequin shrimp sort them out…
Again, timely thread…thank you… and following

Like any animal we put in our tanks it takes a little time to see them become active. Like I said it was about 6-9 months probably closer to 6 when I noticed the shrimp out looking around and I did a close exam of the tanks, rocks and realized I had no sign of stars in any part of the tanks. I had moved them from one tank to another or another section of my multiple stage sump in that time every few weeks when I saw the population of starts dwindle. But I never really thought all the stars in that section were gone but eventually I realized they were indeed gone and not repopulating. It was a lot quicker and easier to just buy cc stars as anyone who let me come get stars had me bagging them and that takes time. Then the lfs near me started bumping prices of the stars first from 5 cents to 25 then to $1 each. I just bought cc stars cheaper and easier. I think the cc stars were $15-20 each for pretty good sized ones little ones were $10. I put the shrimp in their own tank tied to the system and put 2 stars in once a month and that seemed to work well if the stars were the larger ones. The shrimp would eat part of the star and ride it around until they decided it was time to eat again. I had my pair for maybe 2 years before I sold them to someone looking for some. I sold them with the info I had acquired and the assurance that they would either sell them to me at the same price once the stars were gone or they would care for them in the same manor or sell them to someone else with the same intention and keeping us all in the loop. The last guy to get them had a tank fail and had to rush sell everything while I was out of town so I could not get them back and he was unsure who they went to. We all posted in the local forum but never received any answers on who had them. We all loved them and we became friends except the guy whos tank failed I would not have sold them to him and the guy that did was kicking himself for doing so. I found them to be quite personable very often out and not hiding and would almost be waving at you when I came in the room especially if they were hungry.

 

[taricha]

Asterina starfish farm for future harlequin shrimp and Aiptasia farm.

P1 I would like to farm Asterina starfish that my LFS gave to me (15 starfish), how could I do this? I want them to lay asterina eggs, or do they even do that? Is there a way to make them reproduce asexually or by fragging (slicing them in half) to make them grow? I have already done this with...

www.reef2reef.com

Each harlequin eats around 15 asterina per day. So a pair would eat 30 a day, around 900 asterina a month

Or, 1 chocolate chip star each per week

Now some have methods where you have several chocolate chip star, around 6-7. Remove one leg from one chocolate chip at a time and rotate which one you take from, and allow them to regrow. However I talked to my lfs, and the guys there all own harlequin in home tanks and they say they have never been successful with this strategy and it takes a long time for a leg to regrow.

Best bet - sell to a LFS for credit. Mine told me they would gladly buy him back after the tank was cleaned up

my harlequin shrimp also gladly accepts frozen chocolate chip starfish arms.

Once I couldn't easily find the aquilonastra stars in my display, I started feeding arm slices from a choc chip star I had thrown in the freezer. I'll continue this for two weeks, allowing the shrimp time to hunt down as many well-hidden straggler stars as possible, then the shrimp goes back to the LFS.

 

[VintageReefer]

my harlequin shrimp also gladly accepts frozen chocolate chip starfish arms.

Once I couldn't easily find the aquilonastra stars in my display, I started feeding arm slices from a choc chip star I had thrown in the freezer. I'll continue this for two weeks, allowing the shrimp time to hunt down as many well-hidden straggler stars as possible, then the shrimp goes back to the LFS.

Why freeze them? I just put them in the sump and let them clean it

 

[Cheezle]

Was wondering why my little pink goni was closed up the last day or so, took a closer took and it had 2 asterina smothering and eating it. I took them off before taking the pic but this isn't the first time they've eaten my corals. I had a nice acantho and hammer they've eaten.

These little buggers are not to be trusted.

 

[taricha]

I'd love to see if we can't figure out some species ID's to start figuring out which are reef-safe and which may eat zoas (the color is a useful starting point for ID, but isn't the only characteristic needed):

here's some better photographs under magnification...

More pictures in this shared google photos folder.

 

[ISpeakForTheSeas]

Was wondering why my little pink goni was closed up the last day or so, took a closer took and it had 2 asterina smothering and eating it. I took them off before taking the pic but this isn't the first time they've eaten my corals. I had a nice acantho and hammer they've eaten.

These little buggers are not to be trusted.

Very interesting to see them going after non-zoanthid corals for you; I've only seen that with one very darkly colored star (practically black on top), and I can't find the thread again to confirm if it was actually an Aquilonastra star or not (I've seen one thread where it was thought to be an Aquilonastra/"Asterina" star feeding on SPS, but the star in question had visible spikes on it's topside, so it was most likely an Oreasterid star of some kind than an Asterinid).

Any chance you could get clearer pics? Magnification may be necessary, but it could be useful - I do know yours look slightly different than the average Aquilonastra star in the hobby (but that may just be the fact that all of yours pictured have five, fully formed legs).

 

[Timfish]

Got some more comments but first I just want to offer my congradulations again! Your thread is helping clear up the contradictions around the roles of Aqualonastra seastars in aquaria.

. . . One more comment on the question of whether the stars are eating coral tissue or biofilm.
in this frame from the time lapse I posted above, if you look at the polyp circled in yellow - you'll notice it's significantly darker than the others.

The darkened tissue is from part of the skirt/oral disc being removed, and you are seeing the mostly exposed symbionts.
The reason I say that is that during this time, I pulled an actively feeding star off of the mouth of a polyp in that colony and a cloud of brown symbiont dust went into the water, most of the skirt and oral disc was seemingly gone.
So if feeding on the surface films degrades tissue, and they also feed on polyps with degraded tissue all the way down to exposed symbionts... then there is no distinction left to be made - that's just eating coral polyps . . .

But there's another possible explanation for the zoa being darker brown in the video. Melanin is an important part of coral immune systems and is used in combating bacterial infections. Is the aquilonastra remaining on the polyp because of an ongoing bacterial infection. And an infection would also explain the brown tissue sloughing off when the star was ulled off. Clearly the starfish was part of the problem that one zoa had as the digestive process satrfish use would affect any coral if it remained too long. But what is the underlying reason or conditions it stayed on that zoa while the starfish on the one next to it crawled off? Could it be that one zoa had a more acute problem than the other?

This kinda reminds me of the thousands of deaths from Clostridioides difficile (C. diff) infections every year that develop after antibiotics, that help most people, allow C. diff to proliferate. And this is more likely to happen in people with compramised immune systems.

We know immune systems vary at the genotype level in corals. Microbiomes, which are essential parts immune systems are altered by transplanting. Research is showing fluorescing proteins are multifuctional and are important components of coral immune systems (1) (2) (3). This selective behavior you and others have demonstrated certainly is another example calling for the considered and deliberate mixing of species in aquaria but is the problem fundamentally, as aquarists we're not considering immune functions when selecting and promoting variants with brighter coloration in animals? I realize these is a bit esoteric but at teh very least we need to be cognizant these are complex issues we are dealing with and obvious assumptions need to be questioned.

 

[taricha]

Clearly the starfish was part of the problem that one zoa had as the digestive process satrfish use would affect any coral if it remained too long. But what is the underlying reason or conditions it stayed on that zoa while the starfish on the one next to it crawled off? Could it be that one zoa had a more acute problem than the other?

This is true, and it's going to be extremely difficult to answer that question confidently by observation of the starfish-coral interaction.

It'll be easier to answer in big picture statistical way by excluding or not excluding stars to access zoanthids. That is, regardless of what the star is attempting to do - or what the nutrition source actually is, what does its presence or forced absence do to the zoa colony health?

I'll feel more confident of my answer on that after my zoa frags have a few weeks on the sand without any starfish around.

To turn the question around, where does the idea come from that aquilonastra are not predatory? Determining dietary preferences is pretty tricky science.

(likely aquilonastra in my tank from 2016 extruding stomach to digest a live limpet off of the glass - note there was plenty of biofilm on the glass in the area.)

Maybe we should think of them like hermits, omnivorous abilities - diet can vary widely depending on the population size and conditions / food availability in the tank.

 

[Cheezle]

Very interesting to see them going after non-zoanthid corals for you; I've only seen that with one very darkly colored star (practically black on top), and I can't find the thread again to confirm if it was actually an Aquilonastra star or not (I've seen one thread where it was thought to be an Aquilonastra/"Asterina" star feeding on SPS, but the star in question had visible spikes on it's topside, so it was most likely an Oreasterid star of some kind than an Asterinid).

Any chance you could get clearer pics? Magnification may be necessary, but it could be useful - I do know yours look slightly different than the average Aquilonastra star in the hobby (but that may just be the fact that all of yours pictured have five, fully formed legs).

Unfortunately the big fellows eating my hammer and acantho are long gone from my tank.

As for getting a pic, they have found their way back to my goni. It's probably not much help but I scraped him off and took what pic of it I could with my pixel pro 6

Forgot to mention, I'm prying these guys off of my coral. It's not like when I knock them off when cleaning, they're suctioned very tight onto them so they're not just casually crawling on them.

 

[VintageReefer]

I caught them eating an acan a few days ago. 3 acan frags on plugs within 2” of each other. A nice little garden. Each plug with 2-3 heads. All heads target fed and doing fine. All from same seller. Had them all about 2-3 months.

Saw one of these starfish on one of the acans. Now that entire plug is bare skeleton.it had two heads that were opening fine and being fed and viewed daily

Thought the harlequin got rid of them all but apparently a few are left

 

[Timfish]

. . . To turn the question around, where does the idea come from that aquilonastra are not predatory? Determining dietary preferences is pretty tricky science . . .

Watching them interact with various corals in multiple systems freinds have or that I have maintained for up to 4 decades. It seemed obvious they have some selection process and can decide when and what to crawl on to clean stuff up. The information you posted I see as additional evidence they able to sense and choose where to feed to some degree.

Here's an example, this Toadstool is doing one of it's periodic sheddings. The Aquilonastra have been in this system for years but only climb onto the Toadstool when it's shedding. In the first picture you can see the old mucus film, Aquilonastra starfish and areas they have cleaned off. The second picture shows the Toadstool a week later.

How microbial community composition regulates coral disease development - PubMed

Reef coral cover is in rapid decline worldwide, in part due to bleaching (expulsion of photosynthetic symbionts) and outbreaks of infectious disease. One important factor associated with bleaching and in disease transmission is a shift in the composition of the microbial community in the mucus...

pubmed.ncbi.nlm.nih.gov

"How microbial community composition regulates coral disease transmission
Critical to coral disease transmission – or resistance – is the coral's surface mucus layer,
which is produced in part by the coral's endosymbionts [12]. The mucus layer hosts a complex
microbial community, referred to hereafter as the surface microbial community (SMC). Because
the mucus environment is rich in nutrients, microbial population densities there are orders of
magnitude higher than in the surrounding water column [20]. Most established and emerging
pathogens are endemic to the ecosystem and typically present at low numbers in the SMC.
When stressed, the SMC can switch rapidly from a community associated with healthy corals to
diseased corals."

Understanding more about coral's mucus coatings and seeing a selection process clearly demonstrated, the info you posted only reinforces this, I see them not only beneficial but essential.

Your OP intrigues me. We really don't have any way to determine the innate robustness of a coral species or genotype. Looking trough information on wild species there are individual species that are only found in association with corals of their own genus . Could the Aquilonastra specie (variety?) in your OP be used as an indicator species for growers to start quantifying which corals are more likely to have issues in shipping or being mixed with other corals, ie, which will do well in mixed reefs and which should only be kept in with carefully curated tankmates?

. . . (likely aquilonastra in my tank from 2016 extruding stomach to digest a live limpet off of the glass - note there was plenty of biofilm on the glass in the area.)

Well, what was unique about the biofilm on that one limpet? Did that starfish inadvertantly crawl over that limpet as it was grazing along (they do leave tracks)? Did that limpet have a unique problem others don't have? Does that starfish go after other limpets?

Maybe we should think of them like hermits, omnivorous abilities - diet can vary widely depending on the population size and conditions / food availability in the tank.

I've seen all the things people here have posted showing Aquilonastra kill corals. And I've seen all the same species die without any AQuilonastra associated with them. And I've seen all the same species have aquilonastra climbing on them and continue to thrive. I've also seen what's appears to be genus apecific diseases introduced on a "nice healthy" specimen and all the establish colonies of that genus die. It's painful to loose a nice specimen or colony within weeks or months of being added. I've found it even more painful to loose additional animals as a consequence of inadvertantly introducing a disease with an apparent healthy animal. Unfortunately my digging around in the research has shown not only can't colration and growth be used as indicators of health they can be indicators of a diseased animal. Your info has certainly expanded my understanding about Aquilonastra and traits/behaviors to pay closer attention too, not only the individual starfish but the corals they associate with.


As an aside, some may balk at starfish displaying some complex behaviors but in spite of being "brainless" some species do have complex social structures. Here's a couple links some may enjoy perusing:

John Pearse, Don Wobber, Biologists: Sea Star Behavior | Shape of Life

John Pearse, a biologist who studies echinoderms, teamed up with Don Wobber to observe the secret lives of the slow and spiny.

www.shapeoflife.org

The sea star's whole body is a head

‘It’s not at all what scientists have assumed about these animals.’

www.popsci.com

 

[taricha]

On species identification, I reached out to the professionals but had no luck.
I sent an inquiry to the Victoria museum (who O'Laughlin did most of his starfish publications through).
He had passed away in 2022, and their current invert researchers said that they typically rely on locality to help with identification. In the hobby, obviously this doesn't help us much - for instance the only known introduction of aquilonastras that I have in my system is from a LFS in Austin, TX.

 

[ISpeakForTheSeas]

To turn the question around, where does the idea come from that aquilonastra are not predatory? Determining dietary preferences is pretty tricky science.

Some have been studied in lab settings and found to be herbivorous - Aquilonastra corallicola, for example:

"A. corallicola feeds on diatoms and green algae growing on the rock and glass walls of the aquaria."*

Others are thought to be either similar in diet to A. corallicola or to be biofilm feeders. For what it's worth, though, even known herbivores like Chocolate Chip Starfish and Blue Linckia Starfish (both of which are currently thought - with good reason - by the scientific community to be biofilm-feeders) are known to exhibit opportunistic predation in aquaria, with Chocolate Chip Stars eating pretty much anything they can catch, and Blue Linckias being known to prey on Aquilonastra stars, sponges, tunicates, and even (very rarely) corals.

So, while these can be predatory, it would seem they either only go after specific corals for specific reasons (such as the coral having a specific biofilm/microbiome that attracts it), or that they use them as a last-resort famine food.

*Source:

https://www.tandfonline.com/doi/full/10.1080/07924259.2010.548631

 

[Minifoot77]

Some have been studied in lab settings and found to be herbivorous - Aquilonastra corallicola, for example:

"A. corallicola feeds on diatoms and green algae growing on the rock and glass walls of the aquaria."*

Others are thought to be either similar in diet to A. corallicola or to be biofilm feeders. For what it's worth, though, even known herbivores like Chocolate Chip Starfish and Blue Linckia Starfish (both of which are currently thought - with good reason - by the scientific community to be biofilm-feeders) are known to exhibit opportunistic predation in aquaria, with Chocolate Chip Stars eating pretty much anything they can catch, and Blue Linckias being known to prey on Aquilonastra stars, sponges, tunicates, and even (very rarely) corals.

So, while these can be predatory, it would seem they either only go after specific corals for specific reasons (such as the coral having a specific biofilm/microbiome that attracts it), or that they use them as a last-resort famine food.

*Source:

https://www.tandfonline.com/doi/full/10.1080/07924259.2010.548631

So a blue linckia would help reduce asterina stars too?

 

[ISpeakForTheSeas]

On species identification, I reached out to the professionals but had no luck.
I sent an inquiry to the Victoria museum (who O'Laughlin did most of his starfish publications through).
He had passed away in 2022, and their current invert researchers said that they typically rely on locality to help with identification. In the hobby, obviously this doesn't help us much - for instance the only known introduction of aquilonastras that I have in my system is from a LFS in Austin, TX.

Yeah, looking more into ID'ing these to the species level, I can see why (it took a bit of work to piece together what parts of the stars I needed to look at and where to find them on the specimens).

It'll take me a bit to work through, but I may be able to ID most of the stars which I can get microscope pics of - the spinelets (the tiny, spikey little things sticking up in clusters off of the star's skin) are the most important features for ID via the keys (specifically the number of spikes in each cluster and the shape of each spike/spike cluster), so as long as the pics can provide clear images of those spines (both on the top of the star and the bottom) and where specifically they're located on the star (i.e. near the mouth, near the ambulacral groove, etc.), I should be able to ID them.

With your pics, taricha, I can see the spinelets relatively clearly on the actinal side (the side with the star's mouth; the "underside" of the star) but not on the abactinal side (the "topside" of the star).

 

[ISpeakForTheSeas]

So a blue linckia would help reduce asterina stars too?

Yes, but I don't recommend it:

Personally, I currently recommend against trying to keep a tropical, true starfish (Asteroid) species, particularly biofilm-feeding species, except for Aquilonastra stars.

That said, if you're really determined to try keeping them anyway, I'd strongly suggest setting up an Aquilonastra farm, a cryptic refugium to farm sponges, and possibly a colonial tunicate farm as well (all of these should be separate from the Linckia's tank so they can't get to the farm and ruin the "crop") - the Linckias feed on these (they presumably emulate biofilms to some degree), and the most successful Linckia keeping I've seen have always involved at least one of these aspects (typically the Aquilonastra stars).

With Aquilonastra stars alone, I've seen people keep them 2-3 years; with the cryptic refugium sponges involved too, the longest I've heard is ~4 years. Still not good by my calculations, but arguably acceptable if they really only live a decade.

For more info, see the post that quote is from (linked below):

A Challenge to Anti Linckia-ism

I hear a lot of folks say we shouldn’t keep Linckia stars because they starve to death or we don’t know how to keep them alive and they just die within a year or so. I decided to read up on the subject and found a peer reviewed scientific article which described the lifecycle of these stars...

www.reef2reef.com

 

[Timfish]

On species identification, I reached out to the professionals but had no luck.
I sent an inquiry to the Victoria museum (who O'Laughlin did most of his starfish publications through).
He had passed away in 2022, and their current invert researchers said that they typically rely on locality to help with identification. In the hobby, obviously this doesn't help us much - for instance the only known introduction of aquilonastras that I have in my system is from a LFS in Austin, TX.

Sorry to hear about O'Laughlin's death!

They could be from anywhere in my tanks. Some of my first setups had wild Florida live rock. Over the years I've had Tonga branch and Fiji live rock. And I likely could have gotten some from friends systems that used live rock from other locations. Considering some of the questions with taxonomy now reaserchers are looking at DNA, relying on location for species identification may not be as reliable as we'd like. (Here's one example.)

Caught this video last weekend in one of my systems of an aquiloanastra and limpet. Sorry, it's real time.